This invention relate to a method and device for replacing the pipe electrode for the small-hole electric (electrical) discharge machine, which makes a small-hole on the works by the electric discharge machining.
As the prior art which relates to this invention, it is described in Japanese Examined Patent Publication No. 58-28055, Japanese Examined Patent Publication No. 62-27929, Japanese Non-examined Patent Publication No. 3-287318, Japanese Non-examined Utility Patent Publication No. 4-57321, Japanese Examined Patent Publication No. 5-65292, Japanese Non-examined Patent Publication No. 8-290332, Japanese Non-examined Patent Publication No. 9-19830, Japanese Non-examined Patent Publication No. 9-136222 and so on.
In Japanese Examined Patent Publication No. 58-28055, a technology for the electrode replacing by replacing an electrode magazine for normal electric discharge machining is disclosed. However, it is not for a small-hole machining.
In Japanese Examined Patent Publication No. 62-72929, a technology for replacing by plural electrode holder (correspond to the electrode magazine of this invention) is disclosed. However, this technology is not related to the small-hole electric discharge machining that a pipe electrode is used.
In Japanese Non-examined Patent Publication No. 3-287318, a replacing device of the electrode which can be located more precisely and which copes with Flexible Manufacturing System is disclosed by using a board-shaped palette for the chuck.
In Japanese Non-examined Utility Patent Publication No. 4-57321, a technology for replacing a magazine itself is disclosed by using the plural magazine which can store the plural electrode. However, it is difficult to apply for small-hole electric discharge machining, also the magazine and the electrode are not unified.
In Japanese Examined Patent Publication No. 5-65292, a replacing device for the electrode guide by moving the plural electrode guide which have plural different diameter hole straight and horizontally is disclosed, however, it is not a replacement as for an electrode magazine.
In Japanese Non-examined Patent Publication No. 8-229747, an electrode replacing device, which combined with the electrode magazine and an electrode tip guide block, is disclosed.
In Japanese Non-examined Patent Publication No. 8-290332, a technology of the process holding an optional electrode which is picked up from the electrode stock box with the holder to the main shaft chuck, the replacing process of the electrode guide, the electrode replacing device which sets up the plural electrode holder support member in the endless chain which can run in the horizontal direction and which holds an electrode holder with the magnet, the small-hole electric discharge machine equipped the swing prevention guide which has the horizontal groove of the V-shape in cross section, the swing prevention guide can move up and down with the main shaft and can be fixed on the designated position is disclosed.
In Japanese Non-examined Patent Publication No. 9-19830, a technology for the electrode setting device equipped a jig which holds whole electrode holder in the case of making many holes at the same time, setting the plural electrode on the electrode holder is disclosed.
In Japanese Non-examined Patent Publication No. 9-136222, a technology for an automatic replacing of the plural electrode guide by using an electrode guide magazine is disclosed.
The most of these prior electrode magazine is chucked one end of the pipe electrode with collet chuck, and formed as the shape that the part which is close to the other end of the pipe electrode is held or guided. Also, at the time of the pipe electrode replacing, to locate the tip of the electrode precisely on the designated processing point of the work, it is necessary the process of that the tip of the pipe electrode is guided to be inserted in the electrode guide, therefore, a complex moving process and its means were required. Further, to reduce replacing frequency of the electrode, when one tries to use a longer pipe electrode, a thin and long pipe electrode vibrates by the movement at the electrode magazine replacing, he can not proceed to the next guidance insertion process until the standstill of the vibration, therefore, it required longer replacing time and there was a problem that the insertion device had to be prepared.
In view of the above problems of the prior art, it is an object of the present invention to provide a method and a device that the automatic replacing of the pipe electrode is to be performed more rapidly, securely and easily for the small-hole electric discharge machine.
The foregoing and other objects are effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:
The inventor found that the foregoing object could be attained by a method of the replacing the whole electrode magazine which contains an electrode guide which was inserted a pipe electrode, and by using an electric magazine which has a means that the position of the Z-axis direction of the pipe electrode is held when it leaves from the electric discharge machine itself in the replacing of the pipe electrode for the small-hole electric discharge machine which uses an electrode magazine.
This invention will be described in further detail by way of example with reference to the accompanying drawings.
As for the electrode magazine 5 in this invention, to make an automatic replacing of the electrode easily, it is a box shaped body formed by the designated dimension and shape. In the prior, the electrode magazine has a collet chuck which is chucked a pipe electrode, the pipe electrode, and partly, a jig for holding or guiding the near point of the other end of the pipe electrode so that it is removable and mountable.
In the present invention, an electrode guide 4 that was inserted a pipe electrode in addition to the collet chuck 2 and the pipe electrode 1 is mounted on the body. It is obviously different from the described electrode guide magazine in Japanese Non-examined Patent Publication No. 9-136222 in the point that a pipe electrode is inserted into the electrode guide later.
An electrode guide 4 is a guidance part to locate the tip of the pipe electrode 1 precisely in the designated machining part of the work. In prior, it is located on the just top position of the machining part of the work, and originally this is not the object for the replacing.
In the present invention, because of the larger advantage that the pipe electrode can be replaced rapidly and securely, comparing with the demerit that one must prepare for an electrode guide for the pipe electrode replacing in each of the electrode magazines, it mounts the electrode guide 4 too, which was inserted a pipe electrode 1 on the electrode magazine 5.
Generally, because of the outside diameter and the length of the pipe electrode is 0.2 mm to 3 mm, 300 mm to 400 mm respectively, of course when it was chucked one end of the pipe electrode with the collet chuck, even if it was held or guided the other end by some means, the tip of the pipe electrode sometimes comes off the electrode guide when it moves at the replacing because the pipe electrode swings in very big amplitude or is rotated at high speed while the electric discharge is processing. Therefore, it is desirable to equip a swing prevention guide 3. A swing prevention guide 3 is a jig which prevents the vibration for guiding to the almost middle position of the pipe electrode 1 between the collet chuck 2 and the electrode guide 4, and may be a shape indicated in the part of the solid line of the FIG. 1A and FIG. 1B.
It is desirable to adopt the means which almost locates a swing prevention guide 3 automatically in the middle position of the pipe electrode 1 between the collet chuck 2 and the electrode guide 4. A mechanism which consists of the combinations of the belt and the pulley that shows in the FIG. 2A and FIG. 2B is desirable as an example. As the first relation of the mutual position to set a pipe electrode, one end of the belt 18 near the lower pulley 17 is fixed on the magazine body, a fixed part for the collet chuck 2 is attached in the opposition side of the belt near the upper pulley 16, by fixing the rear side of the swing prevention guide 3 near the low part of the movement pulley base 15, and by the principle of the pulley, the swing prevention guide is able to descend only half of the descending distances of the collet chuck 2 which follows the consumption of the pipe electrode 1.
The distance between the upper pulley 16 and the lower pulley 17 may be more than half of the length of the pipe electrode 1 which is set on.
The collet chuck 2 in the electrode magazine 5 descends depend on the consumption of the pipe electrode 1 to the Z-axis direction while the electric discharge is processed. These control can be applied the prior technology such as detecting the electric discharge current so that it is controlled.
When a specific electrode magazine leaves from the electric discharge machine itself, as a means of the present invention of always maintenance the Z-axis position information on the way to process works within the electrode magazine, it is desirable to have the mechanism such an example shown in the FIG. 4A and FIG. 4B.
It is the mechanism that the Z-axis position information at that time is held by pressing the belt 18 against the electrode magazine body through the self-position maintenance chip 8 so that the movement pulley base 15 does not move when the electrode magazine 5 leaves from the electric discharge machine itself, and the self-maintenance chip 8 becomes free from the belt 18 when the electrode magazine 5 is attached and locked to the electric discharge machine itself
The prior technology such as an electric charging means to the pipe electrode 1, an injection means of the processing liquid to the pipe electrode 1, an insulation means between the pipe electrode 1 and other members, the general means which is applicable to use small-hole electric discharge machining in prior arts, and picking up means from the magazine rack of the electrode magazine 5, the attaching and the removing means to the electric discharge machine and the mechanical movement means such as storage to the magazine rack 23 may be applied to the present invention.
According to the present invention, by preparing plural electrode magazine 5 including the electrode guide 4 inserted a pipe electrode 1 in advance on the magazine rack 23, the replacing of the pipe electrode 1 can be performed easily and securely by replacing of the electrode magazine 5.
Also, the insertion process of the pipe electrode 1 to the electrode guide 4 after the replacing of electrode magazine 5 is unnecessary.
Further, when the electric discharge machining resume, the process of position fitting of the pipe electrode 1 becomes unnecessary by having the mechanism which holds the Z-axis position information on the way to process works in the electrode magazine 5 of the present invention.